How often should a thermostat be calibrated for accuracy?

A residential wall thermostat does not adhere to a strict calendar schedule for calibration, but it generally benefits from accuracy checks every one to two years or whenever you notice persistent indoor temperature discomfort. Over time, internal electronic components, known as thermistors, can experience calibration drift due to continuous exposure to thermal expansion and contraction, while dust accumulation around the housing can insulate the sensor. You can test accuracy annually using a trusted independent digital room thermometer placed right next to the wall unit. If you find a discrepancy of more than two degrees between the two devices, you should calibrate the thermostat immediately via its advanced settings menu or clean out accumulated dust. You can verify accuracy when display readings match baseline thermometers precisely.